Báo cáo khoa học: Mechanism of the reaction catalyzed by dehydroascorbate reductase from spinach chloroplasts
Dehydroascorbate reductase (DHAR) reduces dehydro-ascorbate (DHA) to ascorbate with glutathione (GSH) as
the electron donor. We analyzed the reactionmechanismof
spinach chloroplast DHAR, which had a much higher
reaction specificity for DHA than animal enzymes, using a
recombinant enzyme expressed inEscherichia coli. Kinetic
analysis suggested that the reaction proceeded by a
bi-uni-uni-uni-ping-pong mechanism, in which binding of
DHA to the free, reduced formof the enzyme was followed
bybindingofGSH....
